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• Delicate images can be retrieved from tarnished daguerreotypes by tracking the Hg Lα XRF excited with a focused synchrotron X-ray beam at energy just above the Hg L3 -edge if the bulk of the image particles remains intact. Surface corrosion is not an issue. • While the risk of radiation damage is low, ultra bright X-ray can produce radiation damage in scattered spots, an upper bound of flux tolerance has been established. • Image can also be retrieved with tender X-rays (2.5–7 keV) using Ag L α and Hg Mα XRF; the shallow penetration depth of tender X-rays minimizes background. • Tender X-ray imaging in a high vacuum provides the added advantage of measuring the surface sensitive total electron yield and the bulk sensitive fluorescence yield, which in turn can be used for micro-spectroscopy and surface corrosion analysis. We report recent observations using a synchrotron X-ray micro-beam to retrieve images from tarnished 19th century daguerreotypes. We confirm that high quality image can always be retrieved from tarnished plates using Hg L α XRF as long as the bulk of the image particles and their distribution remains intact. We also report results from using tunable tender X-rays (2 - 7 keV) to conduct imaging in high vacuum at energy above the Ag L-edge and the Hg M-edge, extracting images using Ag L α and Hg M α , respectively among others (e.g., S to track corrosion). Images obtained with the surface sensitive total electron yield (TEY) and the bulk sensitive fluorescence yield (FLY) as well as corresponding micro-XANES are reported. Flux tolerance to high intensity X-beam is also explored. These results and their implications for cultural heritage research are discussed. [ABSTRACT FROM AUTHOR]

• High line density MLLG was simulated and proposed to improve the X-ray spectral resolution with high efficiency. • 3000-5000 l/mm MLLG can reach 40 times higher efficiency than the single-layer coated grating in the tender X-ray range. • A 3000 l/mm MLLG was experimentally demonstrated for the first time, showing a high efficiency of 54.5% at 4.4 keV. • The other 3000 l/mm MLLG was demonstrated with a large C ff factor of 4.3 and 23.1% efficiency at 4 keV. Driven by the demand of high efficiency and high resolution monochromators and spectrometers in the tender X-ray range, high line density multilayer coated laminar gratings (MLLG) were designed, manufactured, and analyzed. Theoretical simulations displayed that a 5000 l/mm MLLG could realize high resolution at 3 keV and 40 times higher diffraction efficiency than the single-layer coated grating. For the first demonstration of the high line density MLLGs, two 3000 l/mm laminar gratings were fabricated and coated by Cr/C multilayers with different periodic thicknesses to achieve high efficiency (HE) and high resolution (HR) performance. For MLLG-HE, a maximum efficiency of 54.5% was achieved at 4.4 keV. For MLLG-HR, relatively high efficiency of 23.1%–38.6% were demonstrated with much stronger asymmetric diffraction in 2–4 keV, which can significantly increase the energy resolution of the system. [ABSTRACT FROM AUTHOR]

An optical design study of a beamline proposed for the 3 GeV synchrotron radiation facility, the Shenzhen Light Source, is described. The beamline was designed to cover an energy range from 2.0 to 20 keV with two experimental station, one for X-ray absorption spectroscopy (XAS) experiments and the other for X-ray photon correlation spectroscopy (XPCS) experiments. A 4 m planar undulator with a relatively short magnetic period (20 mm) was used as the radiation source. Horizontally and vertically focusing mirrors separately focus the source along the horizontal and vertical directions, respectively, thus enhancing the flexibility of the beamline. The focus point was employed as the secondary source, and a pair of KB mirrors were used to achieve a near-circular focus spot of about 4. 5 μ m × 4. 5 μ m. A Si(111) DCM was selected to produce the monochromatic light that covers the 2.0–20 keV energy range. When the photon energy is lower than 10 keV, the energy resolution can be better than 1.47 × 10−4 and the total flux is larger than 1 × 1014 photons/s. The longitudinal coherence length is in a few μ m range. With aperture size adjustment, the transverse coherence length at the sample position is approximately 3 μ m and the coherent flux is up to 1012 phs/s for the photon energy around 2.5 keV. This excellent coherence performance can be applied for the purpose of X-ray photon correlation spectroscopy related experiments. [ABSTRACT FROM AUTHOR]